On the streets of China it is a common snack, a dense nougat made from nuts, candied fruits, flour and corn syrup known informally as qiegao — literally “cut cake.” It is shaped into large, thick sheets and sold on the back of motorized tricycles by Uighurs, a central Asian ethnic group from China’s northwestern Xinjiang region. The treat is delicious, but buy it once, and you’ll probably never want to again.

That’s because qiegao is often sold by extortionate means. The unit price is always reasonable, but the vendor might not give you the amount you request. Instead he’ll cut off a chunk that ends up costing vastly more than you expected. Once the slice is cut the peddler won’t take it back and, as he’s probably holding a large knife, it is unwise to argue.

On Monday a report about an altercation over the cake in central Hunan province quickly became one of the most discussed items on Chinese microblogs, revealing a current of frustration about ethnic policy in China. Police in the city of Yueyang reported that a dispute between Uighur vendors and a customer ended in a mass brawl with two people injured and the destruction of about $25,000 worth of qiegao, plus $6,500 in hospital bills and damage to the peddlers’ vehicles. A local customer was arrested and 16 Uighurs sent back to Xinjiang.

The since-deleted message touched off a wave of resentment from Han Chinese. Many felt that the peddlers pulled off the mother of all qiegao scams, receiving enough in damaged-cake compensation to buy a car. One widely reposted image showed a piece of the nut cake set on a ring like a diamond. The sharpest criticism touched on the idea that the Uighurs, as members of an ethnic minority, got off easy. “Uighurs where I live rob, beat and insult people,” wrote one person from central Henan province on Sina Weibo. “You can’t cross a pedestrian bridge without trembling in fear. I don’t understand why the government’s policies allow them to bully Han people.”

China recognizes 55 ethnic minorities that make up just 8% of the country’s population. They are largely concentrated in China’s northern, western and southern border regions. China follows a system of ethnic autonomy based on the Soviet model, meaning they are given nominal administrative authority in their home regions — Xinjiang for the Uighurs, Tibet for the Tibetans and Inner Mongolia for Mongolians — but in practice they have little real autonomy. Ethnic minorities are also given exemptions from the one-child policy and favorable treatment in university admissions. The goal was to break down social and economic barriers between minority groups and the Han majority. In practice, minority groups like the Uighurs still face significant economic discrimination, while preferential policies only heighten resentment from the majority Han.

Sometimes the animosity between Uighur and Han explodes with little warning. In 2009 race riots swept the Xinjiang capital of Urumqi, where young, mostly unemployed Uighur men went on a rampage, attacking Han Chinese. Days later Han vigilantes retaliated, saying the local government was failing to protect them. All told nearly 200 people were killed, according to official reports.

Ilham Tohti, a Uighur economic professor at Minzu University who is often targeted by police for his outspoken views on discrimination in China, said while the problem of crimes committed by Uighurs exists, the qiegao dispute risks further fanning Uighur-Han tensions. “The problem of Uighurs committing crime isn’t as frightening as some media and public figures say it is,” he wrote on his microblog on Wednesday. “This not only harms Uighurs, it also brings about Han society’s rejection of and discrimination against Uighurs.”

On Wednesday the Yueyang police updated their report on the incident, saying the total amount of cake damaged was over 2,700 kg, putting the assessed value at less than $9 a kilogram. A reasonable price, but many people will still think twice about buying.